Clear siloxane-based write-erase coating with low volatile organic character

ABSTRACT

The present invention provides, among other things, compositions with at least one dry-erase characteristic and methods thereof. In some embodiments, provided paint composition comprising a resin part comprising an epoxy, a polysiloxane and an organooxysilane; and a cure part comprising one or more amino-silanes; the resin part and the cure part being designed and selected such that, when combined together, they cure to form a clear surface coating that demonstrates at least one dry-erase characteristic, wherein the composition is substantially free of any opacifying agent or pigment.

RELATED APPLICATIONS

This patent application is a National Stage Entry of InternationalApplication No. PCT/US2013/022429, entitled “CLEAR SILOXANE-BASEDWRITE-ERASE COATING WITH LOW VOLATILE ORGANIC CHARACTER”, and filed onJan. 21, 2013. This application claims priority to U.S. provisionalpatent application Ser. No. 61/612,918, filed Mar. 19, 2012. The entirecontents of each of which are herein incorporated by reference.

BACKGROUND

Dry erase products allow their users to write on a surface and theneasily remove the writing, through multiple cycles. Such products haveproven highly popular with and attractive to consumers, but manydemonstrate inferior properties. There is a continuing need for newinsights on improved dry-erase materials and technologies.

SUMMARY

The present invention encompasses the recognition of certain problemswith coating materials that have write-erase character. The inventionprovides particular insights with respect to siloxanecompound-containing materials, popular in the coatings industry becauseof excellent resistance to radiation (e.g., ultraviolet light), tochemical breakdown, and to chalking, in addition to their environmentalcompatibility. Siloxane compounds generally have low viscosities and canbe used to prepare coatings with high solids content and relatively lowvolatile organic components (VOCs), and have been used to coat suchitems as storage tank exteriors, offshore platforms, bridges, exteriorsof ships, hopper cars and exteriors of railway coaches. The presentinvention relates to a particular set of siloxane compound-containingmaterials; those that cure to form a surface with write-erasecharacteristics.

Among other things, the present invention identifies challenges inproviding materials with sufficient hydrophobicity to achieve dry-erasecharacter (e.g., resistance to penetration from marker solvents and/orpigments) that do not include unacceptably high (i.e., above 100 g/L, oreven 140 g/L) levels of volatile organic components. In someembodiments, the present invention specifically provides siloxanecompound-containing materials that cure to form dry-erase coatings andthat contain less than 140 g/L, or less than 100 g/L VOCs. In someembodiments, provided siloxane compound-containing materials cure toform dry erase coatings characterized in that marks made on the coatingsurface marking material can be erased from the coating to beeffectively invisible, resulting in little or no ghosting, even afterprolonged normal use, for example. In some embodiments, providedsiloxane compound-containing materials cure to form dry-erase coatingsthat maintain their character after about 10 cycles, after about 50cycles, after about 100 cycles, after about 500 cycles, after about1,000 cycles, after about 2,000 cycles, after about 3,000 cycles, afterabout 4,000 cycles, after about 5,000 cycles, after about 6,000 cycles,after about 7,000 cycles, after about 8,000 cycles, or after about 9,000cycles of writing and erasing at the same position. In some embodiments,provided siloxane compound-containing materials show desired performancein specific write-erase tests. In some embodiments, provided siloxanecompound-containing materials cure to a write-erase surfacecharacterized by one or more of 1) average surface roughness (Ra) ofless than about 7,500 nm; 2) a maximum surface roughness (Rm) of lessthan about 10,000 nm, 3) a 60 degree gloss of higher than 70; 4) acontact angle of less than about 150 degrees 5) a porosity of less thanabout 45 percent; 6) an elongation at break of between about 10 percentand about 100 percent; 7) a Sward hardness of greater than about 3; 8) aTaber abrasion value of less than about 150 mg/thousand cycles; and/or9) a sag resistance of between about 4 mils and about 24 mils. In someembodiments, a “dry-erase”/“write-erase” material as described herein ischaracterized by a soak time as defined herein of at least about 4. Insome embodiments, a “dry-erase”/“write-erase” material as describedherein is characterized by one or more of the characteristics describedherein.

The present disclosure also provides the surprising finding that certainpreviously described curable compositions that are characterized byparticular write erase characteristics are sufficiently stable withrespect to such write-erase characteristics that they maintain suchcharacteristics independent of presence or level of an opacifying agent,and particularly of a titanium oxide opacifying agent. The presentdisclosure demonstrates that such opacifying-agent-free embodiments arecharacterized by the surprising and unexpected feature of maintainingone or more write erase characteristics observed in anotherwise-identical opacifying-agent-containing composition. Suchcompositions have the additional desirable attribute that they can cureto form a clear coating, and therefore can convert a surface of anycolor into a write-erase surface.

Definitions

In order for the present disclosure to be more readily understood,certain terms are first defined below.

“Curing” as used herein, refers to a process of setting (e.g., byevaporation (drying) and/or cross-linking) a material to form a coatingon a substrate. In some embodiments, curing includes and/or is performedby exposure to ambient conditions, heat, radiation, and/or bycross-linking (e.g., oxidative cross-linking).

“Solvent-based” as used herein refers to compositions includingsolvents, where the solvents in the composition are predominantlyorganic solvents. Such organic solvents may be used either in theiranhydrous or wet form unless specified otherwise. In many embodiments,the term is particularly applied to liquid compositions.

“Substantially solventless” is used herein to refer to compositions inwhich solvents are present at a level below about 10%, and in someembodiments below about 5% by weight/volume of the composition. In manyembodiments, the term is particularly applied to liquid compositions.

“Solventless” is used herein to refer to compositions in which solventsare present at a level below about 1% by weight/volume of the liquidcoating composition before application to a substrate. In manyembodiments, the term is particularly applied to liquid compositions.

“Ambient conditions” as used herein refers to nominal, earth-boundconditions as they exist at sea level at a temperature of about 45-130°F. Typically, ambient conditions include a temperature within the rangeof 20-25° C., and a pressure around 100 kPa.

“Effectively invisible” as used herein refers to a color differenceDelta E (AE) of less than 20 as calculated according to the ASTM TestMethod D2244 before and after a mark is erased by an eraser.

“Substantially invisible” as used herein refers to a color differenceDelta E (AE) of less than 10 as calculated according to the ASTM TestMethod D2244 before and after a mark is erased by an eraser.

“Alkyl” as used herein, refers to a saturated or unsaturated hydrocarboncontaining 1-20 carbon atoms including both acyclic and cyclicstructures (such as methyl, ethyl, propyl, isopropyl, butyl, iso-butyl,sec-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, propenyl, butenyl, cyclohexenyl, and the like). A linkingdivalent alkyl group is referred to as an “alkylene” (such as ethylene,propylene, and the like).

As used herein, “aryl” refers to monocyclic or polycyclic (e.g., having2, 3, or 4 fused rings) aromatic hydrocarbons such as, phenyl, naphthyl,anthracenyl, phenanthrenyl, indanyl, indenyl, and the like. In someembodiments, aryl groups have from 6 to 20 carbon atoms, from 6 to 15carbon atoms, or from 6 to 10 carbon atoms.

As used herein, “heteroaryl” refers to an aromatic heterocycle having atleast one heteroatom ring atom such as sulfur, oxygen, or nitrogen.Heteroaryl groups include monocyclic and polycyclic (e.g., having 2, 3,or 4 fused rings) systems. Examples of heteroaryl groups include withoutlimitation, pyridyl, furyl, quinolyl, indolyl, oxazolyl, triazolyl,tetrazolyl, and the like. In some embodiments, the heteroaryl group hasfrom 1 to 20 carbon atoms (e.g., from 3 to 20 carbon atoms). In someembodiments, the heteroaryl group has 1 to 4 heteroatoms (e.g., 1 to 3,or 1 to 2 heteroatoms).

As used herein, “aralkyl” refers to alkyl substituted by aryl. Anexample aralkyl group is benzyl.

As used herein, “alkoxy” refers to an -0- alkyl group. Example alkoxygroups include methoxy, ethoxy, propoxy (e.g., n-propoxy andisopropoxy), t-butoxy, and the like.

As used herein, “oxyalkylene” refers to an -0- alkylene group.

As used herein, “alkoxylate” refers to an alkyl-C(O)O. Examplealkoxylates include acetate, stearate, and the like.

As used herein, “halo” includes fluoro, chloro, bromo, and iodo.

A “polyol” as used herein is a moiety that includes at least twohydroxyl (—OH) groups. The hydroxyl groups can be terminal and/ornon-terminal. The hydroxyl groups can be primary hydroxyl groups.

A “polyurethane” as used herein is a polymeric or oligomeric materialthat includes a urethane linkage in its backbone.

As used herein, “epoxy” means an epoxy or polyepoxide polymer, includingmonomers or short chain polymers with an epoxide group at either end.

As used herein, the term “silane compound” is used to refer to anysubstituted or unsubstituted silane. A silane is a chemical compoundcontaining both silicon and hydrogen, that is an analog of an alkanehydrocarbon. That is, a silanes consists of a chain of silicon atomscovalently bonded to each other and to hydrogen atoms. The generalformula of a silane is Si_(n)H_(2n+2). A “substituted silane” has achemical structure that is related to that of a corresponding silaneexcept that one or more of the hydrogen atoms has been substituted witha different chemical moiety. In some embodiments, a substituted silanefor use in accordance with the present invention is a compound whosechemical structure is identical to that of a corresponding silane exceptthat one or more hydrogens on the silane has/have been substituted witha moiety containing an amino group or a hydroxyl group, or both. In someembodiments, a substituted silane for use in accordance with the presentinvention contains one or more substituents (as compared with areference silane) selected from the group consisting of amines,alcoholos, etc.; particular exemplary such groups include, for example,aminoethyl, methoxy, ethoxy, etc. In some particular embodiments, asubstituted silane for use in accordance with the present invention isan aminosilane. One particular example of a substituted silaneappropriate for use in accordance with the present invention is2-amnoethyl-3-aminopropyl trimethoxysilane (DYNASYLAN DAMO), used inExamples below.

The term “siloxane compound”, as used herein, encompasses siloxanes andpolysiloxanes, and includes both branched and unbranched compounds, aswell as side-chain-containing (e.g., organic-side-chain-containing)compounds. As is known in the art, a “siloxane” is a chemical compoundcomposed of units of the form R₂SiO, where R is a hydrogen atom or ahydrocarbon group. Siloxanes are generally recognized to belong to thewider class of organosilicon compounds. Siloxanes for use in accordancewith the present invention can have branched or unbranched backbonesconsisting of alternating silicon and oxygen atoms —Si—O—Si—O—, withside chains R attached to the silicon atoms. More complicated structuresare also known, for example, eight silicon atoms at the corners of acube connected by 12 oxygen atoms as the cube edges. Further, the termas used herein includes polymerized siloxanes, which may have organicside chains (R H), and are referred to in the art as silicones or aspolysiloxanes. Representative examples of siloxane compounds for use inaccordance with the present invention are [SiO(CH₃)₂](polydimethylsiloxane) and [SiO(C₆H₅)₂] (polydiphenylsiloxane). It willbe appreciated that such compounds are sometimes considered by thoseskilled in the art to be a hybrid of organic and inorganic compounds.The organic side chains confer hydrophobic properties while the—Si—O—Si—O— backbone is purely inorganic.

As will be understood by those in the art, the term “substituted” refersto a chemical compound having a structure identical to that of areference compound except that one or more moieties of the referencecompound has been “substituted” with a substituent moiety. In someembodiments, the structures of the substituted compound and referencecompound are identical except that one or more hydrogen atoms in thereference compound has been substituted with a substituent moiety. Inthe broadest embodiments, a substitutent moiety can be any chemicalentity that can bond to the rest of the molecule consistent with rulesof chemical bonding. In many embodiments, a substitutent moiety hasfewer than 100, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30,25, 20, 15, 10 atoms.

In general, a product or material described herein is considered to be a“dry-erase” or “write-erase”, which terms are used interchangeably, ifit is characterized in that it can be written on using a markingmaterials as discussed below, and such writing can be removedsubstantially completely with minimal effort and without the use of anapplied solvent. In some embodiments, a material is considered to be“write-erase” or “dry-erase” if a marking material can be erased fromthe material to be effectively invisible, resulting in little or noghosting, even after prolonged normal use, for example, after about 10cycles (e.g., after about 50 cycles, after about 100 cycles, after about500 cycles, after about 1,000 cycles, after about 2,000 cycles, afterabout 3,000 cycles, after about 4,000 cycles, after about 5,000 cycles,after about 6,000 cycles, after about 7,000 cycles, after about 8,000cycles, or after about 9,000 cycles) of writing and erasing at the sameposition and/or have desired performance in specific write-erase tests.In some embodiments, a “dry-erase”/“write-erase” material as describedherein is characterized by one or more of 1) average surface roughness(Ra) of less than about 7,500 nm; 2) a maximum surface roughness (Rm) ofless than about 10,000 nm; 3) a 60 degree gloss of higher than 70; 4) acontact angle of less than about 150 degrees; 5) a porosity of less thanabout 45 percent; 6) an elongation at break of between about 10 percentand about 200 percent; 7) a Sward hardness of greater than about 3; 8) aTaber abrasion value of less than about 150 mg/thousand cycles; and/or9) a sag resistance of between about 4 mils and about 24 mils. In someembodiments, a “dry-erase”/“write-erase” material as described herein ischaracterized by a soak time as defined herein of at least about 4. Insome embodiments, a “dry-erase”/“write-erase” material as describedherein is characterized by one or more of the characteristics describedherein.

BRIEF DESCRIPTION OF THE DRAWING

The drawing is for illustration purposes only, not for limitation.

FIG. 1 depicts a top view of a writable-erasable product.

FIG. 1A depicts a cross-sectional view of the writable-erasable productof FIG. 1, taken along 1A-1A.

FIG. 2 depicts a cross-sectional view of a droplet of water on a coatingand illustrates a method for determining contact angle.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

This disclosure relates to siloxane compound-based coatings havingwritable-erasable surfaces, products that include such coatings (e.g.,whiteboards), materials that cure to form such coatings, and to methodsof making and using the same. Generally, coatings herein providewritable-erasable surfaces on a substrate. In some embodiments, providedcoatings are produced from one or more materials in an essentiallysolventless, or substantially solventless system as defined herein. Insome embodiments, provided coatings form by curing cure under ambientconditions. In some embodiments, provided coatings cure faster and/ormore completely in the presence of light, heat, and/or other types ofradiation.

When the writable-erasable surface is marked with a marking material,the marking material can be erased to be effectively invisible (e.g.,substantially invisible) with little or no ghosting, even afterprolonged and repeated use. The one or more materials that form thecoatings emit minimal volatile organic compounds (VOCs) after curing onthe substrate. For example, the cured coating includes less than about100 g/L or 140 g/L of volatile organic compounds (“VOC”). The resultingcoatings have many desirable attributes, including one or more of thefollowing: low porosity, low surface roughness, high elongation atbreak, high Taber abrasion resistance, and high Sward hardness.

Generally, while not intending to be bound by any theory, it is believedthat the low porosity of provided coatings makes them substantiallyimpervious to the marking materials, while the low surface roughnessprevents the marking materials from becoming entrapped on the surfacebeyond effective reach of an eraser. After a writable-erasable surfaceis marked with a marking material including a colorant and a solvent,the marking material can be erased from the writable-erasable surface tobe effectively invisible (e.g., substantially invisible).

In some embodiments, a writable-erasable product includes a curedcoating (such as a cross-linked coating) extending upon a substrate andhaving a writable-erasable surface. In some embodiments, a coatingmaterial is applied to the surface as a substantially solventless liquidcomposition, wherein the liquid carrier is a combination of liquid andsolid starting materials, but does not include and/or does not requireaddition of, an organic solvent (such as an alcohol, aceton, ketone, orother organic solvent). Alternatively or additionally, in someembodiments, such a coating material does not contain and/or does notrequire addition of more than about 10% by weight of water. An appliedcoating composition can be cured while on a substrate under ambientconditions.

By way of non-limiting illustration, exemplary coatings and/or coatingcompositions can be formed from one or more parts (e.g., components)each independently including one or more ingredients. In accordance withthe present invention, one or both of the component compositionscontains at least one siloxane compound. A siloxane-compound orsiloxane-compound-containing material (e.g., asiloxane-compound-containing component) can be provided as a solidresin, or in a solvent-based carrier. For example, siloxane compoundsherein, and/or compositions comprising them (e.g., asiloxane-compound-containing material or component) can be provided asliquids, solids, or any combination thereof (powders, solutions,suspensions, mixtures, etc.). Particular exemplary, non-limitingsiloxane compounds appropriate for use in accordance with the presentinvention can, for example, be or comprise one or more cyclic siloxanecompounds such as hexamethylcyclotrisiloxane,octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane anddodecamethylcyclohexasiloxane, and/or one or more linear siloxanecompounds such as hexamethyldisiloxane, octamethyltrisiloxane,decamethyltetrasiloxane and polydimethylsiloxane.

The present disclosure exemplifies coating compositions comprising oneor more materials including one or more siloxane compounds. Exemplarycoating compositions are generated by combining component formulationsthat include at least one resin part (as component A) and at least onecure part (as component B), the cure part including one or more ofsiloxane compounds.

In some embodiments, one or more materials, ingredients, and/orcomponents utilized to produce write erase coating compositions inaccordance with the present invention can be in a liquid carrier. Theliquid carrier can be a result of mixing one or more starting materialsthat are present in a liquid physical state, and/or by combining one ormore starting materials in a solid state with one or more startingmaterials in a liquid state. In many embodiments, some or all of theliquids used in accordance with the practice of the present inventionare solventless. Liquid or non-liquid starting materials can be mixedinto a liquid state starting material to form eitherpart/component—whether the resin part, or the cure part, or both. Aftera resin part and a cure part are mixed together, they form a coatingcomposition that can be applied to the surface of a substrate togenerate a coating that cures to form a writable-erasable surface. Inmany embodiments, the cure part has the effect of hardening thecomposition, whether by cross-linking or other chemical and physicalprocesses. After curing, the coating is hard and smooth andsubstantially non-porous so that it can be marked with a markingmaterial including a colorant and a solvent, and thereafter, the markingmaterial can be erased from the writable-erasable surface to beeffectively invisible (e.g., substantially invisible). While whitecoatings are preferable for “white boards”, the coating can be producedin any desirable color, such as by the addition of colorants and/orpigments to the liquid state composition before curing.

In another aspect, the disclosure describes a method of making awritable-erasable product. A provided method includes applying thecoating described herein to a substrate and curing the coating (e.g.,under ambient conditions) to provide a cured coating defining awritable-erasable surface.

A coating can be formed from one or more materials, components, orparts, each independently or collectively including one or moresubstances including any or all of: a silane, an epoxy, a siloxane, andoptionally other ingredients such as UV absorbers, preservatives, andbiocidal agents, for example. In some embodiments, one or more, one ormaterials are in form of resin solid (e.g., epoxy resin). In someembodiments, at least one of one or more of the materials can beprovided in a liquid state. Optionally, one or more materials areprovided in a solvent carrier, preferably using water as a solventcarrier, and less preferably using an organic solvent.

In some embodiments, a composition can further optionally includeadditives such as a catalyst, a surface additive, a surfactant, awetting agent, a defoaming agent, a pigment, a biocide, and/or acolorant.

In another aspect, the disclosure describes a writable-erasable productincluding a cured coating extending upon a substrate and having awritable-erasable surface. A coating composition described herein can beapplied to a surface, so that the coating forms on the surface. At leastone of one or more materials used in preparing such coating compositionscan be in a liquid state, for example in a substantially solventlesscarrier, curing, the resulting writable-erasable surface can bemarkedwith a marking material including a colorant and a solvent, and themarking material can be erased from the writable-erasable surface to beeffectively invisible (e.g., substantially invisible).

In some embodiments, a catalyst is included, preferably in at least oneof the resin part or cure part, or both. Preferably, a catalyst isincluded in a cure part. In some embodiments, a catalyst can be orcomprise a tin catalyst as discussed below. In certain embodiments, acatalyst can be or comprise dibutyltin dilaurate (DBTDL). In otherexamples, it is provided as triethylamine. In some examples, a UVabsorber is also provided, preferably in a cure part. Sometimes, the UVabsorber is provided as a sebacate, such as1,2,2,6,6-pentamethyl-4-piperidyl sebacate (CAS 41556-26-7).

In some embodiments, where a solvent-based carrier is included, thesolvent can include one or more hydrocarbons (such as saturatedhydrocarbons and unsaturated hydrocarbons), alcohols (such as alkoxyalcohols, ketonic alcohols), ketones, esters (such as acetates), mineralspirits, bio-based solvents, or mixtures thereof. Examples of suchsolvents can include ethyl benzene, toluene, xylene, naphtha(petroleum), petroleum distillates, n-butyl acetate, methyl iso-amylketone, Stoddard solvent, t-butyl acetate, acetone, isopropyl alcohol,2-butoxyethanol, toluene, methanol, propanol, 2-butanol, iso-amylalcohol, methyl amyl alcohol, pentane, heptane, odorless mineralspirits, methyl ethyl ketone, diacetone alcohol, methyl amyl ketone,ethyl amyl ketone, diisobutyl ketone, methyl heptyl ketone, ethylacetate, isopropyl acetate, propyl acetate, isobutyl acetate, n-butylacetate, glycol ether EM acetate, amyl acetate, isobutyl isobutyrate,glycol ether EE acetate, glycol ether EB acetate, 2-ethylhexyl acetate,glycol ether DE acetate, glycol DB acetate, methyl isobutyl ketone,dipropylene glycol butoxy ether, vegetable oil, corn oil, sunflower oil,or their mixtures. However, in the preferred embodiments, any suchsolvent comprises less than 10%, and more preferably less than 5%, andmost preferably less than 1% by weight of the coating composition in itsliquid state (before application to substrate and curing).

In some embodiments, a substrate can be selected from the groupconsisting of cellulosic material, glass, wall (such as plaster orpainted wall), fiber board (e.g., a whiteboard in which the curedcoating can be extending upon a fiber board), particle board (e.g., achalkboard or blackboard), gypsum board, wood, plastics (such as highdensity polyethylene (HDPE), low density polyethylene (LDPE), or aacrylonitrile, butadiene, styrene (ABS)-based material), densifiedceramics, stone (such as granite), and metal (such as aluminum orstainless steel). In some embodiments, the substrate can be selectedfrom a flexible film or a rigid structure.

In some embodiments, a marking material includes a solvent includingwater, alcohols (such as alkoxy alcohols, ketonic alcohols), ketones,esters (such as acetates), mineral spirits, bio-based solvents, or theirmixtures. In some embodiments, the marking material can be erased fromthe writable-erasable surface to be effectively invisible by wiping themarks with an eraser including a fibrous material (such as a papertowel, rag, or felt material). In some embodiments, the eraser is dry orincludes water, alcohol (e.g., ethanol, n-propanol, isopropanol,n-butanol, isobutanol, benzyl alcohol), alkoxy alcohol (e.g.,2-(n-propoxy)ethanol, 2-(nbutoxy)ethanol, 3-(n-propoxy)ethanol), ketone(e.g., acetone, methyl ethyl ketone, methyl nbutyl ketone), ketonicalcohol (e.g., diacetone alcohol), ester (e.g., methyl succinate, methylbenzoate, ethyl propanoate), acetate (e.g., methyl acetate, ethylacetate, n-butyl acetate, t-butyl acetate), mineral spirit, or mixturesthereof.

In some embodiments, a writable-erasable product can take the form of awhiteboard, in which the cured coating extends upon a fiberboard, canform a part of a wall e.g., of a structure, or can form a plurality ofsheets, each sheet including a substrate (e.g., in the form of a paper)having the cured coating extending thereupon.

In some embodiments, prior to combining, the one or more materialsincluding the resin part can be in a first container, and the one ormore materials including one or more cure parts can be in a secondcontainer. Optionally, a catalyst can be combined with the cure partprior to mixing with the resin part.

Embodiments and/or aspects may include one or more of the followingadvantages. Coating surfaces are writable and erasable. The coatings canprovide writing surfaces that exhibit little or no image ghosting, evenafter prolonged normal use. Coatings can be simple to prepare and can beapplied to many different substrates, including both porous (e.g.,paper) and non-porous substrates (e.g., densified ceramics). Coatingscan be applied to various substrates including, but not limited to,chalkboards (e.g., blackboards), whiteboards, drywalls, gypsum boards,plaster, and painted walls. A solvent-based coatings can be applied onthe substrate on-site rather than being manufactured in a factory. Formany substrates, a single coating can provide an adequatewritable-erasable surface. Coatings can exhibit good adhesive strengthto many substrates. Coating components (prior to mixing) can have anextended shelf-life, e.g., up to about three years or even up to sixyears. Coatings can be readily resurfaced. Coatings can cure rapidly,e.g., in less than about 12 to 60 hours, and more preferably betweenabout 24 to about 48 hours, under ambient conditions. Coatings canresist yellowing, as determined by ASTM method G-154, for an extendedperiod of time (e.g., up to 2000 hours or even up to 5000 hours).Coatings do not require UV light or high-energy radiation, such as abeam of electrons, for curing. Nevertheless, in some embodiments, light,e.g., UV light, or heat can be utilized to enhance the curing rate.Coatings can have a reduced tendency to run even when applied upon avertical substrate. Surface gloss of the coatings can be readilyadjusted. The writing surface of the coating can be projectable.Coatings can be hard. Coatings can be substantially impervious toorganic solvents and/or inks. Coatings can have a low porosity. Surfacesof coatings can have a low roughness. Coatings can be impact resistant.Coatings can be made scratch and abrasion resistant. Coatings can berelatively low cost. The coatings can have a high chemical resistance.

Dry Erase Product

Referring to FIGS. 1 and 1A, a writable-erasable product 10 includes asubstrate 12 and a coating 14 (e.g., a cured coating) extending upon thesubstrate 12. The cured coating 14 has a writable-erasable surface 16.When the writable-erasable surface 16 is marked with a marking material,the marking material can be erased from the writable-erasable surface tobe effectively (e.g., substantially) invisible, resulting in little orno ghosting, even after prolonged normal use, for example, after about10 cycles (e.g., after about 50 cycles, after about 100 cycles, afterabout 500 cycles, after about 1,000 cycles, after about 2,000 cycles,after about 3,000 cycles, after about 4,000 cycles, after about 5,000cycles, after about 6,000 cycles, after about 7,000 cycles, after about8,000 cycles, or after about 9,000 cycles) of writing and erasing at thesame position. The visibility, or the lack thereof, of the erasing canbe determined by measuring the color change (Delta E, ΔE) on thewritable-erasable surface using a spectrophotometer (such as the SP-62portable spectrophotometer available from X-Rite), after marking on thesurface and erasing the marking. The color change is a composite ofthree variables, lightness (L*), red/green value (a*), and yellow/bluevalue (b*). The erasability characteristics of the writable erasablesurface 16 can be defined in terms of the ΔE value. In some embodiments,the ΔE for the writable-erasable surface 16 after 5,000 cycles (or evenafter 10,000 cycles) can be less than about 50, e.g., less than about40, less than about 30, less than about 20, less than about 10, lessthan about 9, less than about 8, less than about 7, less than about 6,less than about 5, less than about 4, less than about 3, less than about2, or less than about 1.

In some embodiments, the ΔE for the writable-erasable surface 16 after5,000 cycles (or even after 10,000 cycles) can be in a range of about0.1 to about 10.0, e.g., about 0.1 to about 0.5, about 0.5 to about 1.0,about 1.0 to about 1.5, about 1.5 to about 2.0, from about 2.0 to about2.5, about 2.5 to about 3.0, about 3.0 to about 3.5, about 3.5 to about4.0, about 4.0 to about 4.5, about 4.5 to about 5.0, about 5.0 to about5.5, about 5.5 to about 6.0, about 6.0 to about 6.5, about 6.5 to about7.0, about 7.0 to about 7.5, about 7.5 to about 8.0, about 8.0 to about8.5, about 8.5 to about 9.0, about 9.0 to about 9.5, or about 9.5 toabout 10.0.

It is to be appreciated that the erasability characteristic may also beevaluated based on the differences in L* (ΔL*), without attribution tocolor differences. This evaluation can also be combined with theprogressive abrasion of the coating on an abrader, such as the Taberabrader 4360. The abrasion of the coating can be performed similar tothe ASTM Method D4060. In this instance, the erasability characteristicas a function of the abrasion can be determined by abrading thewritable-erasable surface 16 for a certain number of cycles and thenmeasuring the change in lightness (ΔL*) value after marking on thesurface followed by erasing the marking. Typically, a substrate with acured coating can be loaded on an abrader and abrasive wheels can berotated on the writable-erasable surface 16 for a certain number ofcycles (e.g., about 50 cycles, about 100 cycles, about 150 cycles, about200 cycles, about 500 cycles, or about 1,000 cycles). After eachabrasive cycle, a spectrophotometer (such as the SP-62 portablespectrophotometer available from X-Rite) can be used to measure the L*of the abraded area (L*a) and the writable-erasable surface 16 can bemarked with a marking material (such as an Expo® 1 or Expo® 2, blue orblack marker) and erased (such as with an Expo® felt dry eraser). Aspectrophotometer (such as the SP-62 portable spectrophotometeravailable from X-Rite) can be used to measure the L* value of the erasedarea (L*_(b)). The ΔL* can be determined from the difference of L*_(a)and L*_(b) values. In some embodiments, the ΔL* value for thewritable-erasable surface 16 after 1,000 cycles can be at least about20, e.g., at least about 30, at least about 40, at least about 50, atleast about 60, at least about 65, at least about 70, at least about 75,at least about 80, at least about 85, at least about 90, or at leastabout 99. In some other embodiments, the ΔL* value for thewritable-erasable surface 16 after 1,000 cycles can be at least about65, e.g., at least about 67, at least about 69, at least about 71, atleast about 73, at least about 75, at least about 77, at least about 79,at least about 81, at least about 83, at least about 85, at least about87, at least about 89, or at least about 91. In yet other embodiments,the ΔL* value for the writable-erasable surface 16 after 1,000 cyclescan be from about 65 to about 70, from about 70 to about 75, from about75 to about 80, from about 80 to about 85, from about 85 to about 90,from about 90 to about 95, or from about 95 to about 99.

Advantageously, when the writable-erasable surface 16 is marked with amarking material, the marking material can be erased from thewritable-erasable surface to be effectively (e.g., substantially)invisible.

A marking material can include a colorant (e.g., a pigment) and asolvent such as water, alcohol (such as alkoxy alcohol, ketonicalcohol), ketone, ester (such as acetate), mineral spirit, bio-basedsolvents (e.g., vegetable oil, corn oil, sunflower oil). Mixtures of anyof the noted solvents can also be used. For example, mixtures of two,three, four or more of the noted solvents may be used. Bio-basedsolvents are alternatives to conventional organic solvents and can beobtained from agricultural products. Such solvents can provide lowervolatile organic compounds in coatings and decreased environmentalimpact. A marking material can be selected from any of the industrystandard dry-erase markers.

In some embodiments, the marking material can be erased from thewritable-erasable surface 16 to be effectively (e.g., substantially)invisible by wiping the marks with an eraser that includes a fibrousmaterial. For example, the eraser can be in the form of a disposablewipe, a cloth, or a supported (e.g., wood, plastic) felt. The eraser canalso include a solvent such as water, alcohols (e.g., alkoxy alcohols,ketonic alcohols), ketones, esters, (e.g., acetates), or mineralspirits. Mixtures of any two or more of these solvents can also be used.

Examples of alcohols that can be used in the marking material or theeraser include ethanol, n-propanol, iso-propanol, n-butanol,iso-butanol, benzyl alcohol, 2-(n-propoxy)ethanol, 2-(n-butoxy)ethanoland 3-(n-propoxy)ethanol. Examples of ketones that can be used in themarking material or the eraser include acetone, methyl ethyl ketone andmethyl nbutyl ketone. Examples of esters that can be used in the markingmaterial or the eraser include methyl acetate, ethyl acetate, n-butylacetate, and t-butyl acetate.

Compositions that form the coating 14 can be applied to many differenttypes of substrates, including porous (e.g., paper) and non-poroussubstrates (e.g., densified ceramics). The substrate 12 can be aflexible film or a rigid movable or immovable structure. Examples of thesubstrate include, but not limited to, a polymeric material (such as apolyester or a polyamide), a cellulosic material (such as paper), glass,wood, plastics (such as HDPE, LDPE, or an ABS-based material), a wall(such as a plaster or painted wall), a fiber board (such as a whiteboardin which the cured coating extends upon a fiber board), a particleboard, (such as a chalkboard or blackboard), a gypsum board, densifiedceramics, stone (such as granite), and a metal (such as aluminum orstainless steel). The substrate could be a newly built structure or evenan old and worn out chalkboard, blackboard, or whiteboard. In someinstances, the surface of the substrate can be cleaned by sanding thesurface and priming the surface prior to application of the coating. Insome instances, the surface can also be cleaned with a cleaning agent(e.g., acetone or a mild acid) in order to provide better adhesion ofthe coating to the surface.

Compositions that that form the coating 14, prior to the application onsubstrates, can have a pot life which is the period during which thematerials must be applied on the substrate. In some embodiments, thematerials can have a pot life in a range of about 10 minutes to about 16hours, for example, about 30 minutes to about 12 hours, about 60 minutesto about 8 hours, about 2 hours to about 4 hours, or about 1 hour toabout 4 hours, or about 1 hour to about 2 hours. In other embodiments,the materials can have a pot life of greater than about 6 months, forexample, about 12 months, about 18 months, about 24 months, about 30months, or about 36 months. In the embodiments herein that aresubstantially solventless, the pot life of the composition after mixingthe resin part and any cure part(s) is preferably in a range of about 4to about 6 hours.

Compositions that that form the coating 14, upon application to thesubstrate(s), typically cure under ambient conditions. While notintending to be bound by any theory, it is believed that cross-linkingbetween polymeric chains can influence certain unique properties ofcoatings. In some optional embodiments, the curing can be facilitated byultra-violet (UV) light, thermal means, initiators, electron-beams, andcombinations thereof. The coating 14 on the substrate 10 can cure underambient conditions in from about 4 hours to about a week, e.g., fromabout 4 hours to about 24 hours, from about 8 hours to about 20 hours,from about 12 hours to about 16 hours, from about 1 day to about 7 days,from about 2 days to about 6 days, or from about 3 days to about 5 days.The cured coating 14 can be generally stable and also emit little or noVOCs after curing. Curing under ambient conditions can reduceenvironmental impact and can make the materials safer to use.

The porosity of a coating (e.g., a cured coating) can determine theamount of marking material that can be trapped in the coating. While notintending to be bound by any theory, it is believed that lower porosityof coatings can lead to better writable-erasable surfaces. In someembodiments, the coating 14 can have a porosity in a range of about 1percent and about 40 percent, e.g., about 2 percent and about 35percent, about 2.5 percent and about 30 percent, or about 3 percent andabout 20 percent. In other embodiments, the coating 14 can have aporosity of less than about 40 percent, e.g., less than about 35percent, less than about 30 percent, less than about 25 percent, lessthan about 20 percent, less than about 15 percent, less than about 10percent, less than about 5 percent, or even less than about 2.5 percent.

In some embodiments, a coating (e.g., a cured coating) can have aporosity in a range of about 2 percent and about 45 percent, e.g., about2.5 percent and about 35 percent, or about 3 percent and about 35percent. In some specific embodiments, the coating can have a porosityof about 3 percent, about 33 percent, or about 34 percent.

Materials/parts/compositions/formulations used in preparing write-erasecoatings in accordance with the present invention can be prepared by anyof a variety of approaches, including often by standard techniques knownto one skilled in the art. For example, pre-determined amounts of one ormore ingredient materials to be used can be mixed at required speeds inhigh shear dispersers until the materials are homogeneously dispersed.The degree of dispersion of the materials and pigments can be determinedwith a Hegman gauge. One or more additional ingredients (including allremaining ingredients, if desired, can be introduced, for example at aletdown stage to obtain a final formulation appropriate for packaging.In two-component coating formulations, the two parts can be mixedthoroughly and can be allowed to stand for a period of time before beingapplied on a substrate.

A coating formulation can be applied on a substrate 12 in a single coator multiple coats using a roller, a spray (such as an aerosol spray), abrush, or using other types of applicators. In some embodiments, it canbe painted using a foam roller in a single coat. In some embodiments,the coating (e.g., before or after curing) 14 can have a thickness, T(FIG. 1A), in a range of e.g., about 0.001 inch and about 0.125 inch,e.g., about 0.002 inch and about 0.1 inch, about 0.004 inch and about0.08 inch, about 0.006 inch and about 0.06 inch, about 0.008 inch andabout 0.04 inch, or about 0.01 inch and about 0.02 inch). In otherembodiments, the coating (e.g., before or after curing) 14 can have athickness of greater than about 0.005 inch, e.g., greater than about0.0075 inch or greater than about 0.010 inch. While not intending to bebound by any theory, it is believed that providing a uniform, adequatecoating thickness, T, reduces the likelihood of thin or uncoatedsubstrate portions where marking materials might penetrate.

In some embodiments, a coating (e.g., a cured coating) 14 can have aTaber abrasion value of less than about 150 mg/thousand cycles, e.g.,less than about 100 mg/thousand cycles, less than about 75 mg/thousandcycles, less than about 50 mg/thousand cycles, less than about 35mg/thousand cycles, less than about 25 mg/thousand cycles, less thanabout 15 mg/thousand cycles, less than about 10 mg/thousand cycles, lessthan about 5 mg/thousand cycles, less than about 2.5 mg/thousand cycles,less than about 1 mg/thousand cycles, or even less than about 0.5mg/thousand cycles. Maintaining a low Taber abrasion value can providelong-lasting durability to the coating, reducing the incidence of thinspots which could allow penetration of marking material through thecoating and into the substrate.

In some embodiments, a coating (e.g., a cured coating) 14 can have aSward hardness of greater than about 10, e.g., greater than about 15,greater than about 25, greater than about 50, greater than about 75,greater than about 100, greater than about 120, greater than about 150,or even greater than about 200. Without being bound by theory, theinventors propose that maintaining a high Sward hardness provideslong-lasting durability and scratch resistance to the coating. Markingmaterial entrapped in scratches can be difficult to erase.

In some specific embodiments, a coating (e.g., a cured coating) 14 canhave a Sward hardness in a range of about 10 and about 75, e.g., about15 and about 70 or about 15 and about 55. In some specific embodiments,the coating can have a Sward hardness of about 15, about 22 or about 25.

In some embodiments, elongation at break for a coating can be in a rangeof about 5 percent and about 400 percent, e.g., about 25 percent andabout 200 percent, or about 50 percent and about 150 percent. In otherembodiments, the elongation at break can be greater than about 10percent, e.g., greater than about 25 percent, greater than about 50percent, or even greater than about 100 percent. While not intending tobe bound by theory, it is believed that maintaining high elongation atbreak provides long-lasting durability to the coating and it allows thecoating to be stressed without forming cracks. Cracks can trap markingmaterials making erasure from surfaces difficult and, hence, decreasingthe longevity of the writable-erasable products.

In some embodiments, sag resistance for a coating can be at least about3 mils, e.g., about 4 mils, about 5 mils, about 6 mils, about 7 mils,about 8 mils, about 9 mils, about 10 mils, about 12 mils, about 14 mils,about 16 mils, about 18 mils, about 20 mils, about 22 mils, or about 24mils. In other embodiments, the coating 14 can have a sag resistance ina range of about 4 mils to about 24 mils, e.g., about 5 mils to about 20mils, about 6 mils to about 18 mils, about 7 mils to about 16 mils,about 8 mils to about 14 mils, about 9 mils to about 12 mils, or about10 mils to about 12 mils.

In some embodiments, a writable-erasable surface 16 can have an averagesurface roughness (Ra) in a range of about 0.5 nm and about 7,500 nm,e.g., about 1 nm and about 6,000 nm, about 2 nm and about 5,000 nm,about 5 nm and about 2,500 nm, about 10 nm and about 1,500 nm, about 20nm and about 1,000 nm or about 25 nm and about 750 nm. In otherembodiments, the writable-erasable surface 16 can have an averagesurface roughness (R_(a)) of less than about 7,500 nm, e.g., less thanabout 5,000 nm, less than about 3,000 nm, less than about 2,000 nm, lessthan about 1,000 nm, less than about 500 nm, less than about 250 nm,less than about 200 nm, less than about 100 nm, or even less than about50 nm. In certain embodiments, the writable-erasable surface 16 can havean average surface roughness (Ra) in a range of about 75 nm and about1,000 nm, e.g., about 100 nm and about 500 nm or about 150 nm and about400 nm. In certain embodiments, the writable-erasable surface 16 canhave an average surface roughness (Ra) of about 150 nm, about 300 nm, orabout 1,000 nm.

In some embodiments, a writable-erasable surface 16 can have a maximumsurface roughness (Rm) of less than about 10,000 nm, e.g., less thanabout 8,000 nm, less than about 6,500 nm, less than about 5,000 nm, lessthan about 3,500 nm, less than about 2,000 nm, less than about 1,000 nm,or less even than about 500 nm.

In some embodiments, a writable-erasable surface 16 can have a flatfinish (gloss below 15, measured at 85 degrees), an eggshell finish(gloss between about 5 and about 20, measured at 60 degrees), a satinfinish (gloss between about 15 and about 35, measured at 60 degrees), asemi-gloss finish (gloss between about 30 and about 65, measured at 60degrees), or gloss finish (gloss greater than about 65, measured at 60degrees).

In some specific embodiments, a writable-erasable surface 16 can have a60 degree gloss in a range of about 45 and about 90, e.g., about 50 andabout 85. In other embodiments, the writable-erasable surface 16 canhave a 20 degree gloss in a range of about 10 and about 50, e.g., about20 and about 45. In still other embodiments, the writable-erasablesurface 16 can have a 85 degree gloss in a range of about 45 and about90, e.g., about 75 and about 90. In other specific embodiments, thewritable-erasable surface 16 can have a 20 degree gloss of about 12,about 23, or about 46; or a 60 degree gloss of about 52, about 66, orabout 85; or a 85 degree gloss of about 64, about 78, or about 88.

In some embodiments, to improve the writability and erasability of thesurface 16 of the coating 14, materials can be chosen so that a curedcoating 14 has a surface that is relatively hydrophilic and not veryhydrophobic. Referring to FIG. 1A, hydrophobicity of thewritable-erasable surface 16 is related to its wettability by a liquid,e.g., a water-based marking material. It is often desirable to quantifythe hydrophobicity of the writable-erasable surface 16 by a contactangle. Generally, as described in ASTM D 5946-04, to measure contactangle, 0, for a liquid (such as water) on the writable-erasable surface16, an angle is measured between the writable-erasable surface 16, and atangent line 26 drawn to a droplet surface of the liquid at athree-phase point. Mathematically, 0 is 2×arctan(A/r), where A is theheight of the droplet image, and r is half width at the base. In someembodiments, it can be desirable for the writable-erasable surface 16 tohave contact angle, 0, measured using deionized water of less than about150 degrees e.g., less than about 125 degrees, less than about 100degrees, less than about 75 degrees, or even less than about 50 degrees.In other embodiments, it can be desirable for the writable-erasablesurface 16 to have contact angle 0 above about 35 degrees, e.g., aboveabout 40 degrees, or above about 45 degrees.

In certain embodiments, contact angle, 0, measured using deionizedwater, can be in a range of about 30 degrees and about 90 degrees, e.g.,about 45 degrees and about 80 degrees, or about 39 degrees and about 77degrees. In some specific embodiments, the contact angle can be about 40degrees, for example, about 50 degrees, about 60 degrees, about 73degrees, or about 77 degrees.

In some embodiments, a writable-erasable surface 16 can have a surfacetension in a range of about 30 dynes/cm and about 60 dynes/cm, e.g.,about 40 dynes/cm and about 60 dynes/cm. In some embodiments, thewritable-erasable surface 16 can have a surface tension of about 22dynes/cm, about 25 dynes/cm, about 30 dynes/cm, about 42 dynes/cm, about44 dynes/cm, or about 56 dynes/cm. In some embodiments, thewritable-erasable surface 16 can have a surface tension more than about22 dynes/cm, about 25 dynes/cm, about 30 dynes/cm, about 42 dynes/cm,about 44 dynes/cm, or about 56 dynes/cm.

In general, a coating (e.g., a cured coating) 14 can be formed byapplying (e.g., rolling, painting, or spraying) a solution of thematerial in a solvent-based carrier that can have a sufficient viscositysuch that the applied coating 14 does not run soon after it is appliedor during its curing. At the same time, the solution viscosity should besufficient to permit easy application. In some embodiments, the appliedsolution can have a viscosity at 25° C. in a range of about 75 mPas andabout 20,000 mPas, e.g., about 200 mPas and about 15,000 mPas, about1,000 mPas and about 10,000 mPas, or about 750 mPas and about 5,000mPas.

For testing, a coating (e.g., a cured coating) 14 can be made by castinga material on a fluoropolymer substrate and then curing the material sothat it can have a dry thickness of about 0.002 inch. The cured samplecan then be removed from the fluoropolymer substrate to provide the testspecimen. Testing can be performed at 25° C. Elongation at break can bemeasured using ASTM method D-882; porosity can be measured using mercuryporosimetry (suitable instruments available from Micromeritics,Norcross, Ga., e.g., Micromeritics Autopore IV 9500); surface roughnesscan be measured using atomic force microscopy (AFM) in tapping modeusing ASME B46.1 (suitable instruments, e.g., WYKO NT8000, are availablefrom Park Scientific); Taber abrasion resistance can be measuredaccording to ASTM method D-4060 (wheel CS-17, 1 kg load) and Swardhardness can be measured according to ASTM method D-2134 (Sward HardnessRocker Model C). VOC level(s) can be determined using the EPA Method 24.Gloss can be measured using ASTM method D-523-89 (BYK Tri-Gloss MeterCat. No. 4525). Contact angle can be measured with deionized water usingthe dynamic contact angle method (Angstroms Model FTA 200) using ASTMmethod D-5946-04. Sag resistance can be measured using ASTM method D4400which can be performed by obtaining a draw-down and measuring visuallyby comparison with standard ASTM pictures. Surface tension can bemeasured using AccuDyne Marking Pens. Stormer Viscosity can be measuredon a Brookfield Viscometer by ASTM method D-562 and reported in Krebunits (Ku).

Formulations

The cured coating 14 having the writable-erasable surface 16 can beformed under ambient conditions from an uncured coating formulation. Thecoating formulations, in general, can include the materials describedbelow. In some embodiments, formulations can be or include aone-component system and/or a multi-component system (e.g., atwo-component system). In some embodiments, a coating composition and/orits parts will not cure if denied light and sealed in a substantiallyair-free container. A one-component system, for example, consists of acoating formulation material packaged to be ready for use. Atwo-component system, for example, consists of two coating materialsthat are mixed, upon demand and when desired, to obtain the final liquidcoating formulation prior to application on the substrate.

Silane Compound-Based Epoxy

A silane compound-based epoxy coating formulation can be obtained bymixing an epoxy resin with at least one siloxane compound (silicone, forexample), and thereafter adding at least a cure part. The silanecompound-based epoxy resins can include polyether chains that containone or more epoxide units in their structure. Polyethers have therepeating oxyalkylene units: alkylene substituted by oxygen groups,e.g., ethyleneoxy (—[CH₂—CH₂O]—). In some embodiments, the polyetherchains can have additional functional groups such as hydroxyl (—OH).Curing of epoxy resins can lead to less amount of volatile products.

Due to the unique properties of the epoxide ring structure, curingagents (e.g., catalyst) in a cure part can be either nucleophilic orelectrophilic. Examples of nucleophilic agents include alcohols,phenols, amines, amino silanes, thiols, carboxylic acids, and acidanhydrides. Examples of electrophilic agents include aryl iodoniumsalts, aryl sulfonium salts, and latent acid catalysts (e.g., dibutyltindiacetatonate CAS 22673-19-4, aka 4-pentanedionato-o,o′)-dibutylbis(oc-6-11)-ti; dibutyl bis(2,4-pentanedionato-,o′)-,(oc-6-11)-tin;di-n-butyltin bis(acetylacetonate), tech., 95%; di-n-butyltinbis(acetylacetonate); di-n-butyltin bis(2,4-pentanedionate); di-n-butylbis(2,4-pentanedionate)tin; dibutyltin bis(acetylacetonate); dibutyltinbis(2,4-pentanedionate); dibutyl bis(pentane-2,4-dionato-o,o′)tin; tin,dibutyl bis(2,4-pentanedionato-.kappa.o,.kappa.o)-, (oc-6-11)-;Sn(acac)Bu₂; dibutyl bis(pentan-2,4-dionato-o,Ozinn;bis-(2,4-pentanedionato)-dibutyltin; dibutylbis(2,4-pentanedionato-o,o″)-; di-n-butyltin bis(acetylacetonate),tech.; dibutyltin bis(2,4-pentanedionate), typically 95%; EINECS245-152-0; tin, dibutyl bis(2,4-pentanedionato-o,o′)-, (oc-6-11)-,(molecular formula=C₁₈H₃₂O₄Sn)). In some embodiments, curing agents cancontain one or more nucleophilic groups. Epoxy resins can contain analiphatic (such as cyclic or acyclic) or an aromatic backbone or acombination of both. In some optional embodiments, the epoxy resins cancontain other non-interfering chemical linkages (such as alkyl chains).

A) Resin Part

For example, the coating 14 described in FIG. 1 can be formed from aresin part that includes an epoxy material and a silicon. In someembodiments, a silicon can be or comprise polysiloxane. In addition, asilicon can be or comprise an organooxysilane.

Epoxy-polysiloxane polymers can be obtained by taking an epoxide resinhaving more than one 1,2-epoxy groups per molecule with an epoxideequivalent weight in the range of from 100 to about 2,000 that undergoeschain extension by reaction with the amine groups in a polysiloxane.Such polymers and processes are discussed below as described in U.S.Pat. Nos. 5,618,860 and 5,275,645, the contents of which areincorporated herein by reference.

Exemplary epoxide resins are non-aromatic hydrogenated cyclohexanedimethanol and diglycidyl ethers of hydrogenated Bisphenol A-typeepoxide resin, such as Epon DPL-862, Eponex 1510, Heloxy 107 and Eponex1513 (hydrogenated bisphenol A-epichlorohydrin epoxy resin) from ShellChemical in Houston, Tex.; Santolink LSE-120 from Monsanto located inSpringfield, Mass.; Epodil 757 (cyclohexane dimethanol diglycidylether)from Pacific Anchor located in Allentown, Pa.; Araldite XUGY358 andPY327 from Ciba Geigy located in Hawthorne, N. Y.; Epirez 505 fromRhone-Poulene located in Lousiville, Ky.; Aroflint 393 and 607 fromReichold located in Pensacola, Fla.; and ERL4221 from Union Carbidelocated in Tarrytown, N. Y. Other suitable non-aromatic epoxy resininclude DER 732 and DER 736. Such non-aromatic hydrogenated epoxideresins are desired for their limited reactivity of about two, whichpromote formation of a linear epoxy polymer and prohibits formation of across-linked epoxy polymer. It is believed that the resulting linearepoxy polymer formed by adding the hardener to the epoxide resin isresponsible for the enhanced weatherability of this composition. In someembodiments, a coating composition comprises in the range of from about15 to about 45 percent by weight epoxide resin.

With respect to polysiloxane used to make up a resin part, exemplarypolysiloxanes include, but are not limited to, those having thefollowing formula:R₂—O—[Si(R₁)₂—O]_(n)—R₂where each R₁ is selected from the group consisting of the hydroxy groupand alkyl, aryl, and alkoxy groups having up to six carbon atoms. EachR₂ is selected from the group consisting of hydrogen and alkyl and arylgroups having up to six carbon atoms. In some embodiments, R₁ and R₂comprise groups having less than six carbon atoms to facilitate rapidhydrolysis of the polysiloxane, which reaction is driven by thevolatility of the alcohol analog product of the hydrolysis. R₁ and R₂groups having greater than six carbon atoms tend to impair thehydrolysis of the polysiloxane due to the relatively low volatility ofeach alcohol analog. Methoxy, ethoxy and silanol functionalpolysiloxanes having n selected molecular weights are about 400 to about2000 which are preferred for formulating coating and flooring materialsof the present invention. Methoxy, ethoxy and silanol functionalpolysiloxanes having molecular weights of less than 400 would produce acoating and flooring composition that would be brittle and offer poorimpact resistance. Methoxy, ethoxy and silanol functional polysiloxaneshaving molecular weights of greater than 2000 produce a coating andflooring composition having both a viscosity outside the desired rangefrom about 3,000 to 15,000 centipoise (cP) at 20° C., and are tooviscous for application without adding solvent in excess of currentvolatile organic content (VOC) requirements.

Exemplary methoxy functional polysiloxanes include DC-3074 and DC-3037from Dow Corning; GE SR191 and SY-550 from Wacker located in Adrian,Mich. Silanol functional polysiloxanes include, but are not limited to,Dow Corning's DC840, Z6018, Q1-2530 and 6-2230 intermediates. In someembodiments, a coating composition comprises in the range of from 15 to45 percent by weight polysiloxane. In some embodiments, a flooringcomposition comprises in the range of from one to ten percent by weightpolysiloxane. If the coating and flooring composition comprises anamount of polysiloxane outside each range, the coating and flooringcomposition produced will display inferior weatherability and chemicalresistance. In some embodiments, a coating composition comprisesapproximately 30 percent by weight polysiloxane. In some embodiments, aflooring composition comprises approximately 3 percent by weightpolysiloxane.

With respect to organooxysilane used to make up the resin component,preferred organooxysilanes have the general formulaR₃—Si—(OR₄)₃where R₃ is selected from the group consisting of alkyl and cycloalkylgroups containing up to six carbon atoms and aryl groups containing upto ten carbon atoms. R₄ is independently selected from the groupconsisting of alkyl, hydroxyalkyl, alkoxyalkyl and hydroxyalkoxyalkylgroups containing up to six carbon atoms. In some embodiments, R₄comprise groups having up to six carbon atoms to facilitate rapidhydrolysis of the organooxysilane, which reaction is driven by theevaporation of the alcohol analog product of the hydrolysis. R₄ groupshaving greater than six carbon atoms tend to impair the hydrolysis ofthe organooxysilane due to the relatively low volatility of each alcoholanalog.

Particularly preferred organooxysilanes are trialkoxysilanes such asUnion Carbide's A-163 (methyl trimethoxy silane), A-162 and A-137, andDow Corning's Z6070 and Z6124. A preferred coating composition comprisesin the range of from one to ten percent by weight organooxysilane. Insome embodiments, a flooring composition comprises up to about twopercent by weight organooxysilane. If the coating and flooringcomposition comprises an amount of organooxysilane outside each range,the coating and flooring composition produced will display inferiorimpact resistance and chemical resistance. In some embodiments, acoating composition comprises approximately five percent by weightorganooxysilane. In some embodiments, a flooring composition comprisesapproximately 0.7 percent by weight organooxysilane.

In certain embodiments, a commercially available resin part (includingall ingredients) can be used in accordance with the present disclosure.For example, Can A is PSX 700A (from PPG) can be used as a resin part.

B) Cure Part

A resin part can then be mixed with a cure part. In some embodiments, acure part may include at least one amino-silane and optionally acatalyst. In some embodiments, prior to combining, a first containerincludes a resin part, while a second container includes a cure part.Optionally, a catalyst can be combined and packaged with a cure partprior to mixing with a resin part.

While not wishing to be bound by any particular theory, it is believedthat the curing of a silane compound-based epoxy involves the reactionof an epoxide resin with amine to form a cured epoxy polymer, andhydrolyric polycondensation of polysiloxane and organooxysilane toproduce alcohol and a polysiloxane polymer. When an aminosilane isutilized a cure part, a amine moiety of the aminosilane undergoes theepoxy-amine addition reaction and a silane moiety of the aminosilaneundergoes hydrolytic polycondensation. In a cured form, the resultingcoating can exist as linear epoxy-modified polysiloxane which may havesubstantial advantages over conventional epoxy systems.

Amino-Silane

In some embodiments, an amino-silane can be used in a cure part inaccordance with the present disclosure. Exemplary amino-silanes werelisted and tested in Examples below.

In some embodiments, suitable amino-silanes used in accordance with thepresent invention have the general formula:

where R₁₁ and R₁₀ are independently selected from the group consistingof hydrogen, alkyl, hydroxyalkyl, alkoxyalkyl and hydroxyalkoxyalkylgroups containing up to six carbon atoms. In certain embodiments, R₁₀ ishydrogen. In certain embodiments, R₁₀ is hydrogen.

A cure part can be or comprise one or more aminosilanes. For example,DYNASYLAN 1189 (CAS #31024-56-3) and DYNASYLAN DAMO (CAS #1760-24-3) canbe used alone or together in a cure part in accordance with the presentdisclosure. In some embodiments, any two aminosilanes can be usedtogether in a cure part in a weight ratio of or more than about 0.1,about 0.3, about 0.5, about 0.8, about 1.0, about 1.2, about 1.3, about1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0,about 3.0, about 5.0, about 10, about 20, about 30, about 40, about 50,about 100, or even about 200. In some embodiments, the weight ratio ofany two aminosilanes can be in a range of about 0.1 to about 100, about0.5 to about 20, or about 1 to about 10. In some embodiments, the weightratio of any two aminosilanes can be in a range of any two values above.To give an example, DYNASYLAN 1189 (CAS #31024-56-3) and DYNASYLAN DAMO(CAS #1760-24-3) were mixed in various weight ratios as demonstrated inExamples.

In some embodiments, an amino-silane having amine hydrogenmilliequivalent weigh about or more than about 3 grams, about 4 grams,about 5 grams, about 7 grams, about about 10 grams, about 12 grams,about 13 grams, about 14 grams, about 15 grams or about 20 grams. Insome embodiments, an amino-silane having amine hydrogen milliequivalentweigh in a range of about 4 to about 15 grams. In some embodiments, anamino-silane having amine hydrogen milliequivalent weigh in a range ofany two values above.

As discussed above, a resin part has an epoxy equivalent weight in awide range depending on the epoxy ingredients in the resin part. When acure part is mixed with a resin part, the resulting mixture (e.g., aformulation or mixed composition) has an amine to epoxy equivalentweight ratio depending on the weight ratio of two parts. In someembodiments, the amine to epoxy equivalent weight ratio of a formulationuseful in accordance with the present disclosure can be more than orless than about 1.10, about 1.15, about 1.20, about 1.25, about 1.30,about 1.35, about 1.40, about 1.45, about 1.50, about 1.60, about 1.70,about 1.80, about 1.90 or even about 2.00. In some embodiments, theamine to epoxy equivalent weight ratio of a formulation useful inaccordance with the present disclosure can be about, more than or lessthan about 2.10, about 2.15, about 2.20, about 2.25, about 2.30, about2.35, about 2.40, about 2.45, about 2.50, about 2.55, about 2.60, about2.65, about 2.70, about 2.75, about 2.80, about 2.85, about 2.90, about2.95 or even about 3.00. In some embodiments, the amine to epoxyequivalent weight ratio of a formulation useful in accordance with thepresent disclosure can be about, more than or less than about 3.10,about 3.15, about 3.20, about 3.25, about 3.30, about 3.35, about 3.40,about 3.45, about 3.50, about 3.55, about 3.60, about 3.65, about 3.70,about 3.75, about 3.80, about 3.85, about 3.90, about 3.95 or even about4.00. In some embodiments, the amine to epoxy equivalent weight ratio ofa formulation useful in accordance with the present disclosure can beabout, more than or less than about 4.10, about 4.15, about 4.20, about4.25, about 4.30, about 4.35, about 4.40, about 4.45, about 4.50, about4.55, about 4.60, about 4.65, about 4.70, about 4.75, about 4.80, about4.85, about 4.90, about 4.95 or even about 5.00. In some embodiments,the amine to epoxy equivalent weight ratio of a formulation is in arange of about 1.10 to about 1.50, about 1.20 to about 1.30, or about1.20 to about 1.25. In some embodiments, the amine to epoxy equivalentweight ratio of a formulation is in a range of about 2.10 to about 2.85,about 2.20 to about 2.70, or about 2.30 to about 2.60. In someembodiments, the amine to epoxy equivalent weight ratio of a formulationis in a range of about 2.20 to about 3.00, about 2.40 to about 2.90, or2.50 to about 2.75. In some embodiments, the amine to epoxy equivalentweight ratio of a formulation is in a range of about 2.10 to about 3.00or about 2.45 to about 2.60. In some embodiments, the amine to epoxyequivalent weight ratio of a formulation is in a range of about 2.85 toabout 4.30, about 3.20 to about 3.95, or 3.40 to about 3.75. In someembodiments, the amine to epoxy equivalent weight ratio of a formulationis in a range of about 2.20 to about 3.30, about 2.50 to about 3.00, or2.60 to about 2.90. In some embodiments, the amine to epoxy equivalentweight ratio of a formulation is in a range of about 2.20 to about 4.30or about 2.75 to about 3.55. In some embodiments, the amine to epoxyequivalent weight ratio of a formulation is in a range between (andoptionally inclusive of) a lower value and an upper value. In someembodiments, the lower value is about 1.0, about 1.1, about 1.2, about1.25, about 1.3, about 1.35, about 1.4, about 1.45, about 1.5, about1.55, about 1.6, about 1.65, about 1.7, about 1.75, about 1.8, about1.85, about 1.9, about 1.95, about 2.0, about 2.05, about 2.1, about2.15, about 2.2, about 2.25, about 2.3, about 2.35, about 2.4, about2.45, about 2.5, about 2.55, about 2.6, about 2.65, about 2.7, about2.75, about 2.8, about 2.85, about 2.9, about 2.95, about 3.0, about3.05, about 3.1, about 3.15, about 3.2, about 3.25, about 3.3, about3.35, about 3.4, about 3.45, or about 3.5; in some embodiments, theupper value is about 1.25, about 1.3, about 1.35, about 1.4, about 1.45,about 1.5, about 1.55, about 1.6, about 1.65, about 1.7, about 1.75,about 1.8, about 1.85, about 1.9, about 1.95, about 2.0, about 2.05,about 2.1, about 2.15, about 2.2, about 2.25, about 2.3, about 2.35,about 2.4, about 2.45, about 2.5, about 2.55, about 2.6, about 2.65,about 2.7, about 2.75, about 2.8, about 2.85, about 2.9, about 2.95,about 3.0, about 3.05, about 3.1, about 3.15, about 3.2, about 3.25,about 3.3, about 3.35, about 3.4, about 3.45, about 3.5, about 3.55,about 3.6, about 3.65, about 3.7, about 3.75, about 3.8, about 3.85,about 3.9, about 3.95, about 4.0, about 4.05, about 4.1, about 4.25,about 4.2, about 4.25, about 4.3, about 4.35, about 4.4, about 4.45,about 4.5, about 4.55, about 4.6, about 4.65, about 4.7, about 4.75,about 4.8, about 4.85, about 4.9, about 4.95, or about 5.0. In someembodiments, the amine to epoxy ratio in a provided formulation iswithin a range defined by any such lower value and upper value higherthan the relevant lower value, inclusive of the relevant lower and uppervalues.

Relating to the amino to epoxy ratio, the mixing of a cure part with aresin part dictates the weight percentage of each ingredient or part ina formulation. For example, the weight percentage of a resin part can bein a wide range. In some embodiments, the weight percentage of a resinpart in a formulation used in accordance with the present disclosure canbe or more than about 0.1 wt %, about 1 wt %, about 10 wt %, about 20 wt%, about 30 wt %, about 35 wt %, about 40 wt %, about 45 wt %, about 50wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, about75 wt %, about 80 wt %, about 85 wt %, about 90 wt %, about 95 wt %. Insome embodiments, the weight percentage of a resin part in a formulationcan in a range of about 10 wt % to about 90 wt %, or about 80 wt % toabout 90 wt %. In some embodiments, the weight percentage of a resinpart in a formulation can in a range of any two values above.

Catalyst

Typically, one or more catalysts can be added in a cure part. Usefulcatalysts include metal driers well known in the paint industry e.g.zinc, manganese, cobalt, iron, lead and tin, each in the form ofoctoates, neodecanates and napthenates. Suitable catalysts includeorganotin catalysts having a general formula, R₅Sn(R₆)(R₇)(R₈), areselected from a group consisting of alkyl, aryl, and alkoxy groupshaving up to eleven carbon atoms, and R₇ and R₈ can be selected from thesame groups as R₅ and R₆, or from a group consisting of inorganic atomssuch as halogens, sulphur or oxygen. Dibutyl tin dilaurate, dibutyl tindiacetate, organotitanates, sodium acetate, and aliphatic secondary ortertiary polyamines including propylamine, ethylamino ethanol,triethanolamine, triethylamine, and methyl diethanoi amine may be usedalone or in combination to accelerate hydrolytic polycondensation ofpolysiloxane and silane compound.

In some embodiments, up to about 10 wt % (of total) catalyst may beadded with a cure part to a resin part to speed drying and curing offormulations described herein. In some embodiments, the weightpercentage of a catalyst in mixture of a cure part and a resin part canbe about or less than about 10 wt %, about 9 wt %, about 8 wt %, about 7wt %, about 6 wt %, about 5 wt %, about 4 wt %, about 3 wt %, about 2 wt%, about 1 wt %, about 0.5 wt %, about 0.2 wt %, or about 0.1 wt %. Insome embodiments, the weight percentage of a catalyst in mixture of acure part and a resin part can be in a range of 1-0.1 wt %. In someembodiments, the weight percentage of a catalyst in mixture of a curepart and a resin part can be in a range of about 10 to about 0.1 wt %,about 7 to about 0.5 wt %, or about 5 to about 1 wt %. In someembodiments, the weight percentage of a catalyst in mixture of a curepart and a resin part can be in a range of any two values above.

Hybrid Systems

Some or all of the formulation systems mentioned above may be combinedtogether in a substantially solventless hybrid system. A hybrid systemtypically is an admixture of two types of resins. The hybrid system caneither be a hybrid polymer system in a homogeneous medium or a hybridpolymer system in a non-homogeneous medium (e.g., a hybrid dispersion).Hybrid systems can contain two classes of different polymers or resinswhich interact cooperatively to provide desired properties, possibly ina solvent-based carrier. In some embodiments, the hybrid material in asolvent-based carrier can be part of a one component or a two-componentcoating material.

The coating 14 can be formed from a material in a liquid carrier.Preferably, the liquid carrier includes less than about 10%, and morepreferably less than about 5%, and most preferably less than about 1% byvolume/weight of any solvent-based carrier, e.g., an organic solvent.While not intending to be bound by theory, it is believed that somesolvents whether organic or water-based) can be effective as adispersive vehicle for the pigments and resins in a coating formulationprior to curing. For example, during the application of the formulation,they can aid in achieving an appropriate viscosity of the formulation.However, after the coating has been cured, it can be expected that thereis no residual solvent. Exemplary solvents, when optionally present, caninclude 2-butoxyethanol, ethylene glycol, ethyl benzene, xylenes, methylamyl ketone, isopropyl alcohol, propylene glycol monomethyl ether,ethylene glycol monobutyl ether, butanol, paraffins, alkanes,polypropylene glycol, Stoddard solvent, toluene, ethoxylatedalkylphenol, 1-methyl-2-pyrrolidinone, or 1-ethylpyrrolidin-2-one. Insome embodiments, the solvent can be or includes hydrocarbons (such assaturated hydrocarbons and unsaturated hydrocarbons), alcohols (such asalkoxy alcohols, ketonic alcohols), ketones, esters (such as acetates),glycol ethers, and glycol ether esters. Examples of hydrocarbons includetoluene, xylene, naphtha (petroleum), petroleum distillates, ethylbenzene, trimethyl benzenes, and fractions of hydrocarbon mixturesobtained from petroleum refineries. Mixtures of any two or more of thesesolvents may also be utilized. Examples of alcohols include ethanol,n-propanol, iso-propanol, n-butanol, iso-butanol, benzyl alcohol,2-(n-propoxy)ethanol, 2-(n-butoxy)ethanol, 3-(n-propoxy)ethanol, and2-phenoxyethanol. Mixtures of any two or more of these solvents may alsobe utilized.

Examples of ketones include acetone, methyl ethyl ketone, methyln-propyl ketone, methyl n-butyl ketone, and methyl isoamyl ketone.Mixtures of any two or more of these solvents may also be utilized.

Examples of esters include ethyl propanoate, ethyl butanoate, ethylglycolate, propyl glycolate, butyl glycolate, and isoamyl glycolate,methyl acetate, ethyl acetate, n-butyl acetate, isoamyl acetate, andt-butyl acetate. Mixtures of any two or more of these solvents may alsobe utilized.

Other Modifying Agents in Provided Formulations

Accelerators are agents that speed up the curing process. Exemplaryaccelerators that can be used in the formulation include dibutyltindialkanoate (e.g., dibutyltin dialaurate, dibutyltin dioctoate), andoxazolidine. Acid promoters are also optional agents that speed up thecuring process. Acid promoters include aryl, alkyl, and aralkyl sulfonicacids; aryl, alkyl, and aralkyl phosphoric and phosphonic acids; aryl,alkyl, and aralkyl acid pyrophosphates; carboxylic acids; sulfonimides;mineral acids and mixtures thereof. Examples of sulfonic acids includebenzenesulfonic acid, para-toluenesulfonic acid, dodecylbenzenesulfonicacid, and naphthalenesulfonic acid. Examples of aryl, alkyl, and aralkylphosphates and pyrophosphates include phenyl, para-tolyl, methyl ethyl,benzyl, diphenyl, di-para-tolyl, di-methyl, di-ethyl, dibenzyl,phenyl-para-tolyl, methyl-ethyl, phenyl-benzyl phosphates andpyrophosphates. Examples of carboxylic acids include citric acid,benzoic acid, formic acid, acetic acid, propionic acid, butyric acid,dicarboxylic acids such as oxalic acid, and fluorinated acids such astrifluoroacetic acid. Examples of sulfonimides include dibenzenesulfonimide, di-para-toluene sulfonimide, methyl-para-toluenesulfonimide, and dimethyl sulfonamide. Examples of mineral acids includephosphoric acid, nitric acid, sulfuric acid and hydrochloric acid. Insome embodiments, phosphoric acid, citric acid or a combination thereofcan be utilized as an acid promoter.

Surface additives can modify the surface characteristics (such assurface tension properties, substrate wetting, gloss, feel, and slip) ofthe writable-erasable surface 16. Examples of surface additives caninclude modified polydimethyl siloxanes and polytetrafluoroethylene.

The curable compositions can also contain other optional ingredientssuch as fillers, surfactants, light stabilizers, pigments, opacifyingagents, defoaming agent, surface gloss-modifying agent, biocides,viscosity-modifying agent, dispersing agents, reactive diluents,extender pigments, inhibitors for corrosion or efflorescence, flameretardants, intumescent agents, thermal agents for energy efficiency,additives for protection from UV and/or IR, self-cleaning agents,perfumes, or odor sustaining agents.

In some embodiments, the present invention provides curable compositionsthat are substantially free of one or more such optional ingredients.Indeed, the present invention encompasses the surprising finding thatcertain curable compositions as described herein that cure to becomecoatings characterized by one or more write-erase characteristics aresufficiently stable with respect to those write-erase characteristicsthat particular such optional ingredients can be added or removedwithout requiring adjustment of other components, and in particularwithout requiring adjustment of resin and/or cure components.

In particular, it is understood in the art that opacifying agents, andparticularly titanium oxide opaciying agents, can interfere withreactions between chemical moieties involved in curing. For example,such opacifying agents can sometimes themselves react with chemicalmoieties (e.g., isocyanate, hydroxyl, epoxide groups) that wouldotherwise participate in curing of a curable composition. Thus, it isoften expected in the art that components of a coating composition mustbe adjusted when presence or level of such an opacifying agent ischanged.

The present disclosure, however, provides the surprising finding thatcertain previously described curable compositions that are characterizedby particular write erase characteristics are sufficiently stable withrespect to such write-erase characteristics that they maintain suchcharacteristics independent of presence or level of an opacifying agent,and particularly of a titanium oxide opacifying agent.

The present disclosure therefore confirms and supports the utility andvalue of such curable compositions, and furthermore provides descriptionof those embodiments of such compositions that are substantially free ofany opacifying agent (or at least are substantially free of a titaniumoxide opacifying agent). The present disclosure demonstrates that suchopacifying-agent-free embodiments are characterized by the surprisingand unexpected feature of maintaining one or more write erasecharacteristics observed in an otherwise-identicalopacifying-agent-containing composition. Such compositions have theadditional desirable attribute that they can cure to form a clearcoating, and therefore can convert a surface of any color into awrite-erase surface.

The present inventors further note that it is common in the coatingsfield to develop colored coatings through use of both an opacifyingagent (which renders a composition including it substantially white) andalso a pigment (which imparts color to the composition). Theparticularly remarkable clear compositions whose attributes are definedand described herein include those that are substantially free of one ormore pigments, one or more opacifying agents, or both, and specificallyinclude compositions that are substantially free of any pigment and anyopacifying agent (i.e., are, and/or cure to be, clear).

Several commercial suitable light stabilizers are available from CIBASpecialty Chemicals under the trade names TINUVIN® (benzotriazole,triazine, or hindered amine based) and CHIMASSORB® (benzophenone based).

Wetting agents can modify the viscosity characteristics of the coatingformulations. Examples of wetting agents can include silicone freefamily of agents, Metolat® available from Munzing Chemie GmbH.

Examples of opacifying agents can include zinc oxide, titanium dioxide,silicon dioxide, Kaolin clay, e.g., high whiteness Kaolin clay, ormixtures thereof.

Defoaming agents can release the trapped air in the coatings and canenhance the surface smoothness. Examples of defoaming agents can includepolyethylene glycols, or silicone surfactants, e.g., polyether modifiedpolydimethyl siloxane. Defoaming agents such as the BYK family of agentsare available from BYK-Chemie GmbH.

Examples of viscosity modifying agents include polyurethanes, or acommercial acrylic copolymer, TAFIGEL®, available from Munzing ChemieGmbH.

In some embodiments, a formulation or mixed composition can contain upto 30 wt % of one or more modifying agents. In some embodiments, theweight percentage of a modifying agent in a formulation or mixedcomposition can be about or less than about 30 wt %, about 25 wt %,about 20 wt %, about 15 wt %, about 10 wt %, about wt %, about 8 wt %,about 7 wt %, about 6 wt %, about 5 wt %, about 4 wt %, about 3 wt %,about 2 wt %, about 1 wt %, about 0.5 wt %, about 0.2 wt %, or about 0.1wt %. In some embodiments, the weight percentage of a modifying agentcan be in a range of about 30 to about 20 wt %, about 20 to about 10 wt%, about 10 to about 1 wt %, or about 1 to about 0.1 wt %. In someembodiments, the weight percentage of a modifying agent can be in arange of about 30 to about 0.1 wt %, about 10 to about 0.5 wt %, orabout 5 to about 1 wt %. In some embodiments, the weight percentage of amodifying agent can be in a range of any two values above.

In some embodiments, one or more modifying agents including the examplesdescribed herein can be provided in a resin and/or cure part beforemixing of the two parts. For example, titanium dioxide can be providedin a resin and/or cure part. Additionally or alternatively, agentsincluding, but not limited to, silicon dioxide or silica (e.g., Sylysia350), aluminum oxide, modified urea (e.g., Byk 410), micronized, organicpolymer (e.g., Ceraflour 1000) and combination thereof can be added to aresin part (e.g., Can A of commercially available PSX 700A from PPG).

Certain embodiments are further described in the following exampleswhich are not intended to limit the scope of the disclosure.

EXEMPLIFICATION Example 1

In accordance with many embodiments of the present disclosure, a degreeof hydrophobicity is desirable on a dry-erase coating surface in orderto provide sufficient chemical resistance to penetration from the dryerase marker solvents and pigments. However, the present disclosureprovides an insight that many siloxane compounds useful to generatecoatings with appropriate hydrophobicity show unacceptable VOC contents(i.e., VOC contents above 100 g/L or 140 g/L).

This Example describes testing and characteristics of amino-silanes foruse in dry erase coating. Exemplary amino-silanes are listed in Table 1:

Amine hydrogen SiO Trade Molecular equivalent milliequivalentmilliequivalent/ Chemical Name Name Weight per mole amine/gram gram2-aminoethyl-3- dynasylan 206.36 3 14.53 9.69 aminopropyl 1411methyldimethoxysilane n-butyl-3aminopropyl dynasylan 235.4 1 4.24 12.74trimethoxysilane 1189 3-aminopropyl dynasylan 191.34 2 10.45 10.45methyldiethoxysilane 1505 3-aminopropyl dynasylan 221.37 2 9.03 13.55triethoxysilane AMEO Proprietary silane dynasylan 221.37 2 9.03 13.55AMEO-T 2-aminoethyl-3- dynasylan 222.36 1 13.49 13.49 aminopropyl DAMOtrimethoxysilane

As an example, a resin part as provided in the Can A of commerciallyavailable PSX 700 (from PPG) was utilized to be mixed with a cure partin this Example. Each of these amino-silanes was separately combinedwith a resin part in three different amine to epoxy ratios (i.e., 3.0 to1.0, 2.0 to 1.0 and 1.25 to 1.0). Table 2 illustrates the mixtures madewith dynasylan 1411 as an example to achieve different amine to epoxyratios.

(g) cure part (only (g) resin silane Amine/Epoxy Sample Trial 1 partcompound) Ratio Mixture 1 50 13.64 3.00 Mixture 2 50 9.1 2.00 Mixture 350 5.68 1.25

Furthermore, added as a single variable to each mixture of the resinpart and the cure part were the following three additives:

A non-ionic fluorosurfactant (Polyfox 154N)

A colloidal silica (Nissan Chemical IPA ST-UP), and

TEOS (tetraethyl orthosilicate)

Six amino-silanes at three different amine to epoxy ratios wereattempted and examined with or without one of the above additives.Therefore, a total of 72 samples were prepared and evaluated.

A practical method employed for determining superior vs. inferior dryerase performance was to actually write and erase using commoncommercial dry erase markers on small scale samples of painted outformulations. Typically, samples were painted out using a standard naproller and are evaluated for dry erase performance using the followingsubjective conditions: 1) eraseability—Does a conventional dry erasemarker completely remove after application to the coating surface?; 2)staining—Does a conventional dry erase marker leave a permanent stain onthe dry erase coating surface after application and removal?; and 3)ghosting—Following application and removal of a conventional dry erasemarker is there a visible “ghost” of the original mark left on the dryerase coating?

Each of the above criteria were observed for performance based on asubjective evaluation. The purpose of this was to evaluate the dry erasecoating (formula) under “real world” conditions and usage. The first andsecond conditions (eraseability and staining) were paramount toachieving “acceptable” dry erase performance. Only if a formulationpasses the first of these conditions would it even be evaluated forghosting.

Typical scoring/grading utilized are demonstrated below. Eraseabilityand staining were generally evaluated simultaneously according to thefollowing score (or grade):

-   0—Marker does not erase well at all and leaves a substantial    permanent stain-   1—Marker is very difficult to remove and leaves some permanent    residue-   2—Marker demonstrates substantial difficulty in erasing but leaves    little to no permanent staining-   3—Marker requires moderate effort to erase but leaves no permanent    stain-   4—Eraseability of marker is very good and requires only slight    effort to completely removing marking.-   5—Eraseability of marker is excellent—all markings are completely    removed with very little effort.

The results clearly showed that an amine to epoxy ration of 1.25:1provided substantially better coating performance than the other ratiosexamines. In addition, it was evident that none of the additivecomponents provided any significant improvement to the observations ofsamples with regard to dry eraseability. Our observations furtherconcluded that there was significant difference in performance of twoamino-silane compounds, DYNASYLAN 1189 (CAS #31024-56-3) and DYNASYLANDAMO (CAS #1760-24-3), as compared to the others within the experimentalgroup. To further evaluate the amine to epoxy ratios, additionalexperiments were performed as described in Example 1, using three amineto epoxy ratios: 1.30 to 1, 1.25 to 1, and 1.20 to 1. The results alsoshowed that there was significant variation in dry erase performancedependent upon the relative amine reactivity in using more than oneamine functional siloxane compound.

Example 2

Various components (e.g., components as described in Example 1) can bemixed and cured in the presence of at least an additive (e.g., catalyst,surface modifier, etc.).

For example, the mixtures of components described in Example 1 weremixed with an additive. Exemplary additives include two catalysts(dibutyltin dilaurate (DBTDL; CAS #77-58-7) and K-Kat tin free, a zinccomplex catalyst (XK614)) and a surface modifier (PF 159).

As an example, various amounts of an additive were added into 16 samplesusing mixture 1 from Example 1 as illustrated in Table 3:

Weight of Weight of % mixture #1 additive DBTDL % XK 614 % PF 159 1A 100 0 0 0 1B 9.5 0.5 5 0 0 1C 9.6 0.4 4 0 0 1D 9.7 0.3 3 0 0 1E 9.8 0.2 20 0 1F 9.9 0.1 1 0 0 1G 9.95 0.05 0.5 0 0 1H 9.5 0.5 0 5 0 1I 9.6 0.4 04 0 1J 9.7 0.3 0 3 0 1K 9.8 0.2 0 2 0 1L 9.9 0.1 0 1 0 1M 9.95 0.05 00.5 0 1N 9.7 0.3 0 0 3 1O 9.8 0.2 0 0 2 1P 9.9 0.1 0 0 1

The results of this series of experiments showed that a significantamount of the organotin catalyst (dibutyltin dilaurate) would bebeneficial in order to achieve an acceptable level of dry eraseperformance within the prescribed cure time. These results also aided inour conclusion that a surface modifier is optional, as this had aneffect to increase the likelihood of marker beading on the coatingsurface.

Example 3

Exemplary combinations of components were conducted and evaluated inseries as showed in Tables 4-11:

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 65.0 8.9 0.090 1.40 0.45 65.0 8.6 0.087 1.360.43 65.0 8.3 0.084 1.31 0.42 65.3 8.0 0.081 1.26 0.40 64.7 7.6 0.0771.20 0.38

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 65.0 8.8 0.463 1.41 0.46 65.0 8.5 0.447 1.360.45 65.0 8.1 0.426 1.29 0.43 65.3 7.9 0.416 1.26 0.42 64.7 7.5 0.3951.20 0.39

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 65.0 8.6 0.956 1.40 0.48 65.0 8.3 0.922 1.350.46 65.0 8.0 0.889 1.30 0.44 65.3 7.7 0.856 1.24 0.43 64.7 7.4 0.8221.21 0.41

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 65.0 8.1 2.70 1.41 0.54 65.0 7.8 2.60 1.36 0.5265.0 7.5 2.50 1.30 0.50 65.3 7.2 2.40 1.25 0.48 64.7 6.9 2.30 1.20 0.46

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 65.0 6.8 6.80 1.41 0.68 65.0 6.5 6.50 1.34 0.6565.0 6.3 6.30 1.30 0.63 65.3 6.1 6.10 1.26 0.61 64.7 5.8 5.80 1.20 0.58

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 75.0 2.25 16.5 1.01 0.94 75.0 4.50 14.3 1.220.94 75.0 6.83 11.3 1.41 0.90 75.0 6.83 11.3 1.41 0.90

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 600 36.0 114.0 1.22 7.50 600 54.6 90.0 1.41 7.23600 54.6 90.0 1.41 7.23

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 900 54 171 1.2 11.25 900 68 157 1.33 11.25 90081.9 143 1.44 11.25

Example 4

Further experiments on combinations of two parts without anypigment/opacifying agent were conducted to product a clear coating. Aresin part as provided in the Can A of commercially available PSX 700A(from PPG) was utilized to be mixed with a cure part. A cure part can beor include dynasylan 1189, dynasylan DAMO, and dibutyltin dilaurate asdemonstrated in Example 3. As an example, two parts were mixed using avolumetric aspect ratio of Part A (a resin part) to Part B (a cure part)of 2.5.

Series of exemplary weight mixes of two parts were conducted andevaluated as showed in Tables 12-17:

Resin DYNASYLAN DYNASYLAN Dibutyltin part (g) DAMO (g) 1189 (g)Dilaurate (g) 532 67.0 117.0 8.2 532 63.8 111.4 8.8 532 60.6 105.8 8.4

Rang of wt % on Component total weight Resin part 70-75 DYNASYLAN DAMO8.5-9.3 DYNASYLAN 1189   15-16.5 Dibutyltin Dilaurate 1-2 Pigment 0

Rang of wt % on Component total weight Resin part 75-80 DYNASYLAN DAMO8.5-9.3 DYNASYLAN 1189   15-16.5 Dibutyltin Dilaurate 1-2 Pigment 0

Rang of wt % on Component total weight Resin part 70-80 DYNASYLAN DAMO 8-10 DYNASYLAN 1189 14-17 Dibutyltin Dilaurate   1-1.5 Pigment 0

Rang of wt % on Component total weight Resin part 70-80 DYNASYLAN DAMO 5-10 DYNASYLAN 1189 10-20 Dibutyltin Dilaurate   1-1.5 Pigment 0

Rang of wt % on Component total weight Resin part 70-80 DYNASYLAN DAMO 5-10 DYNASYLAN 1189 10-20 Dibutyltin Dilaurate 1-2 Pigment 0

Example 5

This Example describes additional or alternative testing andcharacteristics of amino-silanes for use in dry erase coating. A resinpart as provided in the Can A of commercially available PSX 700A (fromPPG) was utilized. Exemplary amino-silanes alone or mixed were providedas a cure part, which was then mixed with a resin part at threedifferent amine to epoxy ratios.

To evaluate dry erase performance, a practical method was developed todetermine the soak time of each formulation. Samples were painted to asubstrate and allowed to cure for four days. Then markers were appliedto the cured paint. Each individual marker was applied in an arearoughly two inches wide and six inches long. After thirty minutes, ahalf inch by width of the marking was removed with a dry erase cloth.The cured paint was inspected for eraseability of the marking from itssurface every seven days or until failure was noted. The eraseabilitywas given a subjective numerical value as follows:

-   0—Marker does not erase well at all and leaves a substantial    permanent stain-   1—Marker is very difficult to remove and leaves some permanent    residue-   2—Marker demonstrates substantial difficulty in erasing but leaves    little to no permanent staining-   3—Marker requires moderate effort to erase but leaves no permanent    stain-   4—Eraseability of marker is very good and requires only slight    effort to completely removing marking.-   5—Eraseability of marker is excellent—all markings are completely    removed with very little effort.

Similar to Examples 3, exemplary combinations of components wereconducted and evaluated in series as showed in Tables 18 and 19:

Amino/ SY350/Propylene Resin DYNASYLAN Epoxy Carbonate part (g) AMEO (g)Ratio mixture 330.6 135 3.56 25.2 330.6 132 3.48 64.0 330.6 132 3.4832.0 330.6 132 3.48 96.4 330.6 162 4.28 30.2 330.6 108 2.85 20.2 330.6142 3.75 26.5 330.6 128 3.38 23.9 330.6 149 3.93 27.7 330.6 122 3.2222.7

Resin DYNASYLAN DYNASYLAN Amino/Epoxy Dibutyltin part (g) DAMO (g) 1189(g) Ratio Dilaurate (g) 532 63.78 111.45 2.76 8.76 532 67.00 117.00 2.908.20 532 63.80 111.40 2.76 8.80 532 60.60 105.80 2.62 8.40 532 66.97117.02 2.90 9.20 532 60.59 105.88 2.62 8.32 532 70.15 122.59 3.04 9.64532 57.41 100.21 2.48 7.89 532 76.54 133.74 3.31 10.52 532 51.02 89.162.21 7.01 532 82.91 144.88 3.59 11.39 532 44.65 78.01 1.93 6.13 53215.96 117.04 2.07 7.17

All literature and similar material cited in this application,including, patents, patent applications, articles, books, treatises,dissertations and web pages, regardless of the format of such literatureand similar materials, are expressly incorporated by reference in theirentirety. In the event that one or more of the incorporated literatureand similar materials differs from or contradicts this application,including defined terms, term usage, described techniques, or the like,this application controls.

The section headings used herein are for organizational purposes onlyand are not to be construed as limiting the subject matter described inany way.

Other Embodiments and Equivalents

While the present disclosures have been described in conjunction withvarious embodiments and examples, it is not intended that they belimited to such embodiments or examples. On the contrary, thedisclosures encompass various alternatives, modifications, andequivalents, as will be appreciated by those of skill in the art.Accordingly, the descriptions, methods and diagrams of should not beread as limited to the described order of elements unless stated to thateffect.

Although this disclosure has described and illustrated certainembodiments, it is to be understood that the disclosure is notrestricted to those particular embodiments. Rather, the disclosureincludes all embodiments that are functional and/or equivalents of thespecific embodiments and features that have been described andillustrated.

We claim:
 1. A dry-erase paint composition comprising: a resin partcomprising an epoxy, a polysiloxane and an organooxysilane; and a curepart comprising one or more amino-silanes; the resin part and the curepart being designed and selected to have an amine to epoxy equivalentweight ratio in a range of about 1.3 to about 5, wherein the paintcomposition is substantially free of any opacifying agent or pigment. 2.The dry-erase paint composition of claim 1, wherein the cure partfurther comprises a catalyst.
 3. The dry-erase paint composition ofclaim 1, wherein the one or more amino-silanes is selected from2-aminoethyl-3-aminopropyl methyldimethoxysilane, n-butyl-3aminopropyltrimethoxysilane, 3-aminopropyl methyldiethoxysilane, 3-aminopropyltriethoxysilane, 2-aminoethyl-3-aminopropyl trimethoxysilane or anycombination thereof.
 4. The dry-erase paint composition of claim 1,wherein the resin part and the cure part, when combined together, cureto form a clear surface coating characterized by a dry-erasecharacteristic is selected from the group consisting of an averagesurface roughness (Ra) of less than about 7,500 nm; a maximum surfaceroughness (Rm) of less than about 10,000 nm; a 60 degree gloss of higherthan 70; a contact angle of less than about 150 degrees; a porosity ofless than about 45 percent; an elongation at break of between about 10percent and about 100 percent; a Sward hardness of greater than about 3;a Taber abrasion value of less than about 150 mg/thousand cycles; a sagresistance of between about 4 mils and about 24 mils, and combinationthereof.
 5. The dry-erase paint composition of claim 1, wherein theresin part and the cure part, when combined together, cure to form aclear surface coating characterized in that, when its surface is writtenon with a marking material comprising a colorant and a solvent, thesolvent comprising one or more of water, alcohols, alkoxy alcohols,ketones, ketonic alcohols, esters, acetates, mineral spirits, ormixtures thereof, the marking material can be erased from the surface ofthe write-erasable material to be substantially invisible for more than100 cycles of writing and erasing at the same position.
 6. The dry-erasepaint composition of claim 1, wherein the resin part and the cure part,when combined together, cure to form a clear surface coatingcharacterized by a soak time of at least about
 4. 7. The dry-erase paintcomposition of claim 1, having volatile organic compounds (VOCs) of lessthan 140 g/L.
 8. The dry-erase paint composition of claim 1, having VOCsof less than 100 g/L.
 9. The dry-erase paint composition of claim 1,wherein the resin part is in a first container and the cure part is in asecond container.
 10. A dry-erase product comprising: a curablecomposition extending upon a substrate, the curable composition beingcomprised of a combination of a resin part comprising an epoxy, apolysiloxane and an organooxysilane; and a cure part comprising one ormore amino-silanes, wherein the curable composition has an amine toepoxy equivalent weight ratio in a range of about 1.3 to about 5, andwherein the curable composition is substantially free of any opacifyingagent or pigment and is characterized in that it cures under ambientconditions to form a clear surface coating characterized by at least onedry-erase characteristic.
 11. A method of forming a dry-erase product,the method comprising: applying a paint composition to a substrate toform a coating that cures to provide a clear surface, wherein the paintcomposition comprises: a resin part comprising an epoxy, a polysiloxaneand an organooxysilane; and a cure part comprising one or moreamino-silanes, the resin part and the cure part being designed andselected to have an amine to epoxy equivalent weight ratio in a range ofabout 1.3 to about 5, they cure to form a clear surface coating thatdemonstrates at least one dry-erase characteristic, wherein the paintcomposition is substantially free of any opacifying agent or pigment.12. A paint composition comprising: a resin part comprising an epoxy, apolysiloxane and an organooxysilane; and a cure part comprising one ormore amino-silanes, which one or more amino-silanes comprise acombination of 2-aminoethyl-3-aminopropyl trimethoxysilane andn-butyl-3-aminopropyl trimethoxysilane; the resin part and the cure partbeing designed and selected such that, when combined together, they cureto form a clear surface coating that demonstrates at least one dry-erasecharacteristic, wherein the paint composition is substantially free ofany opacifying agent or pigment.
 13. The paint composition of claim 12,wherein the paint composition has an amine to epoxy equivalent weightratio in a range of about 1 to about
 5. 14. The paint composition ofclaim 13, wherein the at least one dry-erase characteristic is selectedfrom the group consisting of an average surface roughness (Ra) of lessthan about 7,500 nm; a maximum surface roughness (Rm) of less than about10,000 nm; a 60 degree gloss of higher than 70; a contact angle of lessthan about 150 degrees; a porosity of less than about 45 percent; anelongation at break of between about 10 percent and about 100 percent; aSward hardness of greater than about 3; a Taber abrasion value of lessthan about 150 mg/thousand cycles; a sag resistance of between about 4mils and about 24 mils, and combination thereof.
 15. The paintcomposition of claim 13, wherein the clear surface coating ischaracterized in that, when its surface is written on with a markingmaterial comprising a colorant and a solvent, the solvent comprising oneor more of water, alcohols, alkoxy alcohols, ketones, ketonic alcohols,esters, acetates, mineral spirits, or mixtures thereof, the markingmaterial can be erased from the surface of the write-erasable materialto be substantially invisible for more than 100 cycles of writing anderasing at the same position.
 16. The method of claim 11, furthercomprising: before the applying step, a step of combining the resin partand the cure part to have the amine to epoxy equivalent weight ratio inthe range of about 1.3 to about 5, thereby forming the paintcomposition.